The goal of the Breast Imaging Biostatistics Core (BIBC) is to provide study design, biomathematical modeling, data analysis, result interpretation, and manuscript preparation expertise to enhance the quality of work performed by all project investigators. Moreover, this BIBC will provide comprehensive clinical data management and research computing services for the Program Project, facilitating a broad range of collaboration. The aims of the BIBC are to: 1. Biostatistics a) advise investigators on study design issues, including sample size/power considerations, for all scientific protocols; b) conduct statistical analyses of data to address the research hypotheses defined in the project-specific proposals; c) assist with preparation and writing of final reports, abstracts, manuscripts, and future research proposals; d) conduct exploratory analyses that may lead to generation of new hypotheses. 2. Data Management a) implement a framework to facilitate data management and statistical analyses for all projects; b) design and implement procedures for tracking the flow of data through various study phases; c) advise investigators on coding, data entry and validation, quality assurance, and reporting; d) design, test, implement, and maintain database structures and application programs for this project.